The data shown below represent the age (in weeks) at which babies first crawl, based on a survey of 12 mothers. Complete parts (a) through (c) below.
52 30 44 35
47 37 56 26
52 30 47 26
Click here to view the table of critical correlation coefficient values for normal probability plots. Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. Click here to view the table of critical $t$-values.
(a) Draw a normal probability plot to determine if it is reasonable to conclude that the data come from a population that is normally distributed. Choose the correct answer below.
Since the correlation between the expected $z$-scores and the observed data, \boxed{} , is \boxed{} the critical value \boxed{}, it is \boxed{} reasonable to conclude that the data come from a population that is normally distributed.
(Round to three decimal places as needed)
(b) Draw a boxplot to check for outliers. Choose the correct answer below.
Does the boxplot suggest that there are outliers?
A. Yes, there is at least one point that is greater than the third quartile or less than the first quartile.
B. Yes, there is at least one point that is outside of the 1.5(IQR) boundaries.
C. No, there are no points that are outside of the 1.5(IQR) boundaries.
D. No, there are no points that are greater than the third quartile or less than the first quartile.
(c) Construct and interpret a 95% confidence interval for the mean age at which a baby first crawls. Select the correct choice below and fill in the answer boxes to complete your choice.
(Round to one decimal place as needed. Use ascending order.)
A. There is a 95% probability that the mean age at which a baby first crawls is between \boxed{} weeks and \boxed{} weeks.
B. We are 95% confident that the mean age at which a baby first crawls is between \boxed{} weeks and \boxed{} weeks.
